Most closed bow boats are still rated for 6 people, so if an open bow is not absolutely necessary, than that may keep your costs down and save you some $$$ for a tower and some fat sacks.
If you are wanting an open bow, I saw a purple Sport Nautique for sell in Belton, TX last year for 17k and I think you can get some of the older Sport Nautiques for less than that. The only problem may be not having $$$ left over for a tower. Also, I have seen some open bow MC PS 190s, as well as some Malibu Euro F3 Sunsetters for less than that.
Check out www.boattraderonline.com
Both should have plenty of boats for sell.
BTW, what area of Texas are you from?