i went with a Hope XC wheel and spacers, on purpose, so i had the option of putting gears in there at a later date.
fine on a hope hub, as there are 4 bearings along its width, so no problem with side loads.
i wouldnt even think about it on a cheaper hub, you'll bend the axel.
i chose an XC over a pro2, as a normal pro2 would require a 50 quid steel freehub body as an extra purchase.
the hope Pro2 single speed hubs will accept 5 cogs of a 9spd cassette if it comes to it (i believe)
48 pickups, makes a massive difference.
24 pickups makes a massive difference too.
compared to 11 in a normal deore hub.