Stay with what you know ...and like..../ but in handguns these days, often you get what you pay for...there is a lot of "junk" out there, if you go cheap.
N frames.....model 27's or 28's in S&W in .357 mag ....and probably look at the L frame model 686's as well. To me, a 4" barrel in an L or N frame fits the bill for defense - and would be the compromise you're looking for / with a 6" being more of a trail gun in my view. Prices are all over the map on S&W revolvers....but there are still a lot of guns out there at a good value...you just need to shop for older models.
In semi-autos ...Colt is making 1911's again and doing a nice job and they're affordable / or even on the lower end of many of the 1911's out there. You can get 1911's in most any caliber you want these days ....but 9mm and .45 acp are probably the most popular.
Some other semi-autos you should probably shoot - to see if you like the grip angle and the controls and the triggers....are a variety of the Sig Sauers....( 226's are their full sized model ) - Sigs are built solid, but have features that you may not realize like decockers, DA-SA triggers, etc...so spend some time looking at them / but I'd also suggest you at least shoot the Springfield XDM's - grip angles are real similar to the 1911.
For affordable ammo in a semi-auto stay with a 9mm. Caliber is often debated on this and other forums ...but its about shot placement / not caliber.