I am fairly sure my next purchase will be a fretless 6, because I really liked my old fretless 5 (had to sell to pay off other gear...) and I would like to have a little more range. At first I was going to go with a 5 with a high C because usually when I need the C I don't need teh B in the same song. My band has a few songs where the guitarist plays simple bass lines and I play lead. That in mind, would it be a stretch to get a six string tuned E-A-D-G-C-F ? My idea is that I could play all my standard bass stuff as well as some chord parts. I also like to experiment with melodies and such. If I did this, what would be a good string maker to order the C and F from? I would want to just order those two in sets, because the high gauges don't tend to last near as long.