Based on the description you gave, I would probably use the 7" shakespeare spinning setup for crankbaits, inline spinners, finesse plastics, drop shots (even lighter weight/short leader Carolina rigs). Just run some 6-10# low-viz Mono line and have fun.
I do not have a lot of experience with entry level baitcasting combos. I learned to fish exclusively on spinners, and was an experienced fisherman before I ever touched a baitcast. So, I waited until I could buy a solid bait casting setup that I knew would have the features that I would want.
As Chuck D alluded, I would try a 6'6" Medium Heavy rod with a 6.4:1 ratio reel for your first baitcaster. I would suggest stringing it with 14-18# Flourocarbon for several reasons. First, that line will feel familiar to your standard mono when casting, though Flouro is much stiffer and more sensitive. Second, Flouro is still heavy enough to fish most cover that a novice is going to feel comfortable attempting anyway, though not as tough as braid. You can always try braid later, but I find it to be a niche line that is not as versatile as Flouro. On this setup you can fish offset spinners, texas rigs, jigs, and really any lure with a large single hook or rigs that are heavy or require sensitivity.
I took a quick look around the net and found a few solid baitcasting setups for under 80 bucks that might work, such as this one on sale: http://www.gandermountain.com/modperl/product/details.cgi?pdesc=GSX-Tournament-Reel-RH-Vortex-Casting-Rod-Combo-66-Med-Heavy-1-pc&i=97166&aID=504AC2&merchID=4006
I have also heard a few people say that these are decent for the money: http://www.walmart.com/ip/Abu-Garcia-Black-Max-Baitcast-Combo/19716434
Also, my brother-in-law swears by the pfluegar templar baitcasting reels, which he picks up on ebay for under 35 bucks. He pairs that reel with an IM6 graphite MH rod from Gander Mountain ($40) for one combo, and another templar with a 6'6" cheap Abu Garcia rod for his second. Of course, you could pair that reel with any rod you choose.
If you know anyone that could let you borrow a baitcaster you might want to try a few out before you decide which one to buy. I found that centrifugal vs. magnetic braking systems are really the most make or break feature for my personal casting experience and style. I like centrifugal breaking systems and many inexpensive combos are magnetic only (the pfluegar templar is one of the cheapest centrifugal braking reels I have seen). Try reels with both braking types before you buy, if you can. Further, if you find a reel you think you like, try it on a different rod length and power. You may find that what you are really feeling is the rod and not the reel. A MH power baitcasting combo feels way different than a med power spinning combo. Expect that.
Good luck, have fun. Give yourself time to learn with a baitcaster. They can be frustrating at first, but are well worth the learning curve.
Kyle