I highly recommend the 5100's. I did consider doing spacers myself just because I got impatient trying to save the money for leveling/lifting. But After a lot of research I realized it doesn't cost that much more for the 5100's and the install, unless you're doing it yourself, cost the same anyway.
I can't speak for the ride of the spacer lift but I've had my 5100's for a couple of months now along with the rear leaf tsb (aal) and love the ride! I was worried it would ride too rough but it's actually better. It may be just a touch stiffer but in a good way, less body roll and just feels tighter. I love my set up.
With that said I'm at 1.75. If you go 2.5 I can't say but have heard it does ride rough.
Also I don't know if you have an SR5 or TRD Off Road? I believe the SR5 has the same coils as my sport. The Off Roads have a progressive coil which does ride rougher with 5100's so I hear.