You've already got a control version of The Captain both ends, yes?
My recommendation would be to leave a Captain on the front and put something like a Racing Ralph, Fast Trak, Crossmark (or maybe Larsen, SM8, Ikon) on the back, but I ride mostly dry, rocky trails and that's what works round here.
Also, although you said you don't want to go tubeless, if you do then it decreases rolling resistance even more!
There's a lot of choice in tyres, and you might not like the feel of what other people do. Keep an eye on the special offers on Chain Reaction, you can often pick up tyres from Michelin/WTB/whoever for about a tenner - it's a good way to experiment.