The problem I'm facing is that the 2x10 Jensen/Bugera speakers I have are 2x4Ω and all the 10 inch speakers listed on Eminence's site are all 8Ω.

Are the differences in ohms that big of a deal?

Also, the Jensen's are rated at 35 watts a piece, if I go with a 50 watt speaker, what if any impact would it have on my loudness and tone?