You might like to check out the
www.britishblades.com site. I am sure that this topic has been extensively discussed over there. You may even find something suitable in the classified adds there.
I am very partial to the Cold Steel Voyager knives, but they are about £50-70, cheaper than some, but possibly too expensive for what you want. The nice thing about the BritishBlades forums is that many people there are collectors, so you get second hand prices on mint condition knives.
Chris