my thoughts,
bigger wheels can be good to a certain extent, too big or too wide and you have dramas.
# keep the offset as close to possible to oem wheels so rims and tyres don't hit suspension
# use an online tyre size calculator to determine the correct tyre size and profile compared to originals for your speedo
#check the said tyre prices locally to see if it is worth the money *** this is important if you are restricted to maximum widths, ie my 1991 daihatsu charade can only go to 185 width on the rear without modifying the guard and tyres in 17" are $340 compare to similar sized 14" being under $100
# you may need to put flares on the guards if they poke out too far from the guards, best to check with local transport dept what is and what isn't legal
# if they are secondhand best to get them checked for buckles, cracks, roundness and previous repairs, nothing worse than driving along and hearing wobwobwob from an "egg buckle" plus it ruins tyres quicker,
as for the ride quality yes it will suffer a bit and be a bit bumpier but unless you are going to a sprayon type tyre ie 30 profile and below, it shouldn't be too bad, your handling may change but would not be really noticable without suspension mods.
also just for interest, every time i have gone wider wheels my fuel economy does suffer, sometimes not too much other times quite dramatically.