Hi
I would recommend a used POD (line6) or Boss GT. They both sound decently
for that budget
The POD is very user friendly. U can connect it easily to your PC and get predefined patches of various artists.
The amp modeler of the POD is better than the GT's but the GT is has better effects for my taste.
You should clarify to yourself, what are the main purposes: The Amp modelers or the effects?
If you wish to mimic specific sounds i would recommend the POD for its great amp modeler?
If you already have a good amp and some experience in sound shaping and want to play further with the sound, i would recommend the GT.
You have also the Zoom products which are cheaper but don't sound good.
Good luch
wsosfr