plate is in sheets (like 4x8, sometimes bigger) and bar is long thin strips (usually 20+') 3/4 is way too thick for a jeep (and heavy), thats larger than what they'ed use on a tank recovery tank. as long as you have it shapped like a C or I, 1/4" is more than strong enough, if your just going with a flat piece accross the frame rails, then 3/8 or 1/2. if you have a harbor freight in your area, they sell a universal winch plate for less than you could probly buy the raw metal, I used it and wench regularlly with it (pulled a 1 ton dually out the other day, its strong enough)
Sold) 94 YJ, 4.0L 5 sp manual, Hard top, 33/12.50s, 4.10 ring&pinions, Polished D30 w/Aussie front, 8.8 rear w/ LS, 2.5" RC, 2" BL, 5/8" booms, TJ flares, SYE, custom F/R bumpers and rock sliders, 8k winch, dual optimas, HO alt.
2) (Sold) 99 TJ, mustang 5.0 GT 40, AX15/231J, trektop, 37x12.50r17 cooper STT, superlift 6" long arm, D30/44 w/ ARBs & yukons, customized warn bumpers, custom sliders, 12K winch w/ synthetic rope, custom paint
3) 2007 JKU being built now