Macloud shows an interesting one - a 1917 Browning. Phil Miller has a nice looking one for sale for $12,200 and also shows an HK51B for $11,500. Check it out [url]albums.photopoint.com/j/AlbumList?u=1803420[/url]
In your shoes, I'd go for a full auto 1919 or 1917. A few more years and you'll be kicking yourself for not buying one sooner. Even if you don't have somewhere to shoot it regularly, you won't be sorry. I only take mine out a couple times a year, but when I do, its a couple thousand rounds, and its always worth it. The Brownings are appreciating better than most 16's and Uzi's and they're getting harder to find. They ain't up to M60, MG34 or MG42 rates yet, but it won't be long. Hell, I bought two of them about two or three years ago for less than one would cost you now. An ANM2 is a real screamer for about $10k (spend the rest on spare parts and a good mount).
A nice collectable Colt would be good too. You'll never lose on a factory M16, especially an A2 or 635. You could do a factory A1 and possibly have enough left for a Barrett M82A1.
A good MP5 conversion will do you well also. For $11k you could get a decent sear gun, maybe even an SD, and have enough left over for a sear ready 33, 53, 91, or 51.
[img]wsphotofews.excite.com/002/jL/Yf/rR/uF15846.jpg[/img]
THINK BELTFED