I have about 400 dollars to spend for an amp, plus about 100 dollars worth of trade ins for a halfstack
Its between the Peavey ValveKing 100 and a Line 6 Spider 2 halfstacks
which is the best?
and what are the pros and cons of each amp?
Pshh, dude, Neither really IMO. The AD100VT is better than the spider. For 500, look at used and the Peavey Classic series or Crate Palomino. Just stay away from the spider
"F*ck off with your sofa units and strine green stripe patterns, I say never be complete, I say stop being perfect, I say let... lets evolve, let the chips fall where they may." -

Tyler Durden
Id go with the valveking. Its a really great amp (all tube!) for the price. It gets pretty decent distortion and clean sounds and should sound great with your epis.
Valveking, its tube, great tone variations. I guess the line 6 might have a wide array of setting and flashing buttons but the quality of the digital tones is of inferior quality. For a rough $500 may i suggest going for a quality combo? Half stacks in todays world of home studios and mic'd pa systems are unnecessary. I guess unless your after the 4x12 bass response or just the presence of having one.
The Set-Up

Gibson Les Paul/Fender MIA Deluxe Strat --> MXR Super comp --> Boss DD-3 --> Dunlop Crybaby --> Need an amp, wanna sell me one?
The presence of one is always awesome to me, but if you dont want to fil up your pedalboard with effects get the spider half stack and a footswitch cause you can save channels on the spider. as for the vavle king i have no opinion cause i never played one.
Schecter C-1 Artist
Line 6 Spider ll 75
Ibanez Weeping Demon Wah
EHX Metal Muff
EHX Nano Small Stone
Alvarez FF60WR

Labyrinth Within
valveking. i had the burden of having to gig with one one time. ive never touched a spider again. ever.