Peltor/AO Worktunes are a possibility, but I really don't like headphones. It's a comfort issue more than anything else. I don't feel nearly as alert to things around me, when I have tried similar headphone setups.
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
Though it is of course, a personal taste issue.. I think that you will find a tractor radio without headphones or a cab will be a battle for bandwidth.. if you will. The radio will have to be turned up over the engine.. which on my NH 1920 at mowing speed.. is quite a decent level.
I've worn headphones on the tractor and am real comfterable with them. Most of the important engine noises come over as vibration anyway.. besides.. the headphones will help protect your hearing along with letting you hear the music at a lower SPL.
I use my Peltor Worktunes when mowing -- something I have not found a way to do if I wear a straw hat. A ball cap works fine, but I'd like more sun protection.
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
I had that same problem.. I eventually got a semi-safari style had that works great. Has an oversized bill like a large ball cap.. and them has a stif yet flexible band of material all around the back.. covers the ears good... Goes over a medium szed set of headphones too. And the best feature is it has a small cotton lanyard with clip on it that you can clip to your collar... when/if the cap blows off.. that hat only falls and lays on your back.. rather than sucking under the mower and turned into mulch.. ( like my hat before that.. )
A cheap alternative that I think is better than a mounted sterio is a walkman with a set of ear phones that can go right under a set of ear muffs. I got a very nice compact sony walkman with digital tuning and a lock button so that you don't accidentally change the tuner for about $30 and a set of ear phones for $5 at Fred Meyers. The best kind of ear phones are the type that actually go slightly inside the ear and have a soft rubber piece that hooks around the top of the ear. These are comfortable for hours and are much less prone to need repair than a fixed sterio. Just my $.02.