Legs.. Need size...

My legs struggled to grow until I split my leg workouts into two separate days.

I do Quads on a Wednesday and hamstrings on Sunday.

thats exactly what ive done for the last few months, got some decent gains from it, but need more now

Stiff-legged deadlifts will target the hams and will have you walking like a cripple for a week,

@trubore, when I was doing a split routine for legs, I was pushing for twice a week which definitely helped me put on size, I've always struggled with leg size but a superset helped me with that prob, ok I don't have the biggest legs ever but from what they use to be to now big improvement. Superset goes like this, start with leg extension till failure then go straight to doing squats as this will incorparate your glutes and hammis to push your quad to the next level, do about 4 Sets with rest in between, there after do 45deg leg press or hak squat. This helped me, hope it will for you. The only thing is what works for one may not work for another. Most important thing I think is your intesity and being able to add some poundage every week or two.

Just squat in a rack. No need for a spotter then.
I wouldn't use the smith machine for the world.

Also if you're looking to add real volume to your quads, you're gonna have to go ATG. Also mix it up with frontsquats, hacksquats, boxsquats etc.