Looking to get a Powell for T-rigs and jigs in the 1/4oz-1/2oz range. I plan on spooling it with 12lb line. What would you recommend the 703, 704, 733 or the 734?

I just bought myself a Powell 734C for 3/8 and 1/2 oz baits. You should probably go with a 733C for 1/4 to 1/2 oz.

Based on the line size you are using, I would go with a Medium Heavy.

I use Powell Heavy's but I fish heavier line and some pretty thick cover most of the time.

733

Give Powell customer service a call.  I've gotten in-depth answers from them.