Good message. You included in your message what you will be doing with your tractor purchase.. many don't.
If it was just you, and the wife wasn't an issue, I might reccomend an older ford from the late 50's... say an 860. Reason being is they have live hyds, ive pto, and some had power steering... though they didn't have rops.
This kind of machine would be on the bare edge of go/no go for your circumstances. I see the clutch still being an issue, if the 1600's clutch is too hard. The lack of a rops is a problem too. ( plenty of HP though.. somehting like up to 45 on some models depending on engine ). ford 860 can go from as little as 2500$ ( there is one currently in the equipment trader magazine for this price ) to 4500 depending on condition.
Bottom line.. if your wife is driving it... I would look at something with power steering.. especially since you want a front end loader.
A remote possibility would be a ford from the 60's with a SOS tranny. Most people will tell you horror stories about SOS trannies being fragile. It is all in how the owner used / abused the machine usually. .. Still probably no rops till you get to the bigger tractors, or in to the 70's. I think you may have to look for somehting other than old iron, if it has to be a dual purpose machine, as once you find something something small enough for the wife to operate.. it may be inadequate for the job. For instance... a farmall cub ( or even A ) these have nice offset seating.. are small and agile.. steer way easy.. Clutch is soft.. are easilly setup for belly mower ( 4'? ) and I've seen one arm loaders for them. Technically this amchine fits your needs... loader.. mower, etc. However.. mowing 6 ac with a 4' mower will take some time..
Though let me give you some advice about horses. If you have more than 1 horse per acer... I doubt you will need to mow anything other than trails in the woody area, or clean up around the edges.
Oh yeah.. one other thing.. many of the older loaders were power up, gravity down, and trip bucket. Unlike our power up/down/dump spool setup of today. Though many were also converted to modern spool setups, so it is not completely out of the question to see an older say 860/2000/3000 with a full hyd loader.. etc.
If price is a major issue, I suggest you look at some of the newer import units.. like branson, eicher, and especially Jinma. Jinma is a chineese tractor. They are not on the same quality line as the 'big 3' brands.. however they are also priced lower. For instance.. you can get a bottom of the line 20hp model 2wd rops, power steering pto/hyds / live. and a canopy etc.. for less than 4k$.. brand new. Pop that up just a bit and go to 4wd.. Bump up to 25hp, and a loader, and still probably less than 7500.. 25 hp puts you right on the edge for a 5' mower. ( figure another 600-1200 for a 5' mower depending on brand ). If 4' mower is fine, your selection drops and the price drops a little ( 495 - ??? ).. also.. if you use a 4' mower.. you don't really need the 25hp... 20 would be fine. For that fact.. you don't have to have 4wd... though pow st. is a must... ( though you may ~want~ 4wd with the loader.. etc... your call. 20hp, 2wd, and a loader comes out pretty cheap... dealerbase is growing too. ( no I don't sell em' /forums/images/graemlins/cool.gif.. I just collect tractors.. and the jinma's and other imports are finally reaching the level of quality where they are actually viable in the us hobby/small farm market .. though i wouldn't use them in a commercail venture...yet).
As far as working on them.. I would choose a dealer that also provides service, as well as parts ordering... some things may be somehting that you can do if you are wrenchy.. if you aren't the wrench sort.. forget about an antique...
Other options are jap imports.. yanmar comes to mind as one of the most durable brands. hard workers. Just make sure you can get parts/service, or again.. if you are wrenchy. all you need is parts.....
Speaking of the asian brands ( chineese / japaneese ).. keep in mind that the operators platforms are not 'um' roomy compaired to american standards.. though.. I see them being fine for a small wife.. etc.
If you do go antique.. with the wife in mid .. stay away from the big monsters.. especially if she has a hard time with a clutch...these old high torque monsters can hurt you fast if you are not real comfterable with the controlls. Also, some have non-standard controlls.. like the 50's era and earlier JD's use had clutches.. also case models in that era, etc. ( AC as well.. ) Though the hand clutch may be a bit 'easier' to engage / disenage.. lots to worry about for someone who isn't 'one with the tractor' I've got a 1950 JD 'B' trike.. I love it... easy starting.. easy steering due to being a trike.. even easy hand clutch... would I want it as a loader tractor? Probably not... not unless I had a 3rd arm.. one of the clutch, one for the steering wheel, and one for the loader spool valve.
Good luck and more importantly.. be safe,
Soundguy