Geedub, it's simple to me.
HST... you are rightly thinking about its ease of use... and it is likely the one thing that will make the tractor consumately usable by the both of you. I consider HST a safety item..braking, precise movement, no jerky, no clutch slips, etc.
50 hp is what you need, or a couple more.. there WILL be things that you will attempt to do where the hp WILL make a big difference... you have the acreage and heavy stuff (trees, etc.) that dictates that you need to go to a heavy tractor and as much hp as you can get. Go light on horsepower and you will be struggeling with stuff... and it can get dangerous with too few hp... this is kinda like the HST... you just really need it.. some think you need 60 and that might be better, but you will be able to do, IMHO, everything you need to do with a 50+ hp .. but 40/45hp is just a little too light. I struggled with too few hp for a long time, amazing how much more I get done now.
a FEL will be mandatory
possibly a grapple
box blade likely
dual rear remotes
hydraulic top link some day
4 wheel drive
R 1's for traction although R4's which I have do just fine for me.
quick attach.. sooooo handy
heavy duty bucket, quick attach, and toothbar
seems like everybody simply has to have a shredder
put good lights front and rear on your ROPS, you will be glad you did.
Net.. your original thoughts were very close, go a little more horsepower, see if there is any way you can get around the features above, go used if you have to stay in the $$ you listed. Personally, I'd go for a used Kubota long before a new gray market. Reliability of Kubota is phenominal, IMHO, and worth paying more now for avoiding repairs later, but that's just me.