While I'm sure its not evident, I'm ever so slightly partial to the Lee-Enfield (points if you can guess my favorite version). Because of that I, personally, would pick an enfield any day over a mauser.
However, if you are looking for a shooter, I would strongly consider looking into a mauser of some sort. 7.92mm ammo is much more prevelant at the moment and far cheaper than .303 ammo. The 150ish grain 7.92mm is very plesant to shoot, however the 198grain ammo will leave a bruise on your shoulder if you fire it for a while.
The sights on K98k's aren't too too bad and its quite easy to hit pie plates at 100 yards with the rifle.
If you're looking for collector value/interest I'd look for a 98K that hasn't been peened out (there are some that have turned up in the recent lots coming in), however most will be mix-masters and would need a bit of work to be true collectors. If you just want to shoot I'd look into one of the turndown bolt yugos, or some of the VZ24s as those are essentially K98ks but were selling for a hair over $100 here a while back.
That said, the Lee-Enfield is a great rifle. My #1MkIII is quite accurate, the magazine capacity is good and the action is super. I don't think you could go wrong with one, the only thing I think that would make them a hands down knock out winner would be if you could find one .308.
However, in either case do expect to spend some time looking for one. Its best to check out a lot before you drop the cash as the quality of K98k's and #4's that I've seen recently has varied widely. I picked up a rather nice #4 that is in cosmetically good condition, but appears to have been rebarreled before it was put away so the bore is literally brand new. This is in stark contrast to all of the other #4's at the shop I bought mine at, as most of those rifles had bores that looked like the surface of the dark side of the moon (i.e. sucked in all the light and lots of craters). I'd sense that the K98k's are somewhat similar, however I haven't had the opportunity to check out a lot of those yet.
Anywho, good luck in your search and let us know what you get!
Cheers!
Lithgow303