You have an awful lot of really good options, especially among the custom makers on this forum. You also haven't given us much to go on, so I'm going to suggest 2 of my all-time favorites that are a reasonable size to actually carry and get some use out.
Fallkniven F1- 4" blade, convex blade (easiest to sharpen, cuts well), sheath is functional, but not spectacular, but you'll have enough money left to get a custom kydex if you want to.
And, the already mentioned RatManDu- a bit larger and heavier, but a seriously great knife. I have an Azwelke sheath that I am very satisfied with, and that gives me lots of carry options.
Both of these knives have huge followings, and will stand up to anything you're likely to throw at them. I also think either one would make a great first, or even, 1 and only fixed blade. Let us know what you end up with and how it works out.