Purple and Green Pumpkin are great colors for plastic worms. I fish a Senko rigged Texas style with do weight most times. Works good in heavy cover but you need to be sure to give it slack line, wacky is easier to fish and better in open water.
I've built rods for close to 50 years, nice hobby and you can really get what you want. Not really a money saver unless you would normally buy top end stuff.
You can get a bigger Gamakatsu hook in most molds. Typically different weight jigs have different hooks and generally you want the hook to match the plastic and weight is used to adjust drop speed. There is no reason to use a different hook size for a 1/4 or 1/2 oz jig with the same 4" swim bait.
Not sure which lure you are talking about. Jig hooks Gamakatsu are shorter than Mustad or VMC. Bigger is not always better and these are all good hooks.
I build my own, what you get for a $100 of components is equivalent to rods that retail for 250 - 500. I make a lot of the baits as well. I'm a little nuts about having stuff just how I like it.