I eat a fair number of loquats from trees in 25 gallon pots. Loquats will stand a pretty light soil (lots of perlite) so the pots are not to difficult to drag around.

Obviously the popular and safe bet is New Dawn, however bloom varies for some as far as repeat. It is definitely most vigorous though and easily gets to 20ft once it matures. Mine is in it's 1st year and it is every bit of 9ft right now and still going. New Dawn is mostly a white, with a pink tinge to it. From a distance it tends to look mostly white though or faintly pink. Many people claim New Dawn doesn't have much of a fragrance, but mine definitely has one, especially when there are many blooms on at one time. It's certainly not strong, but what the blooms lack in strength, they make up for in numbers. Where exactly are you training it on your porch? Are you putting up white lattice, along the fence, etc? I am SURE there are people with many more suggestions and even better ones from their own experiences. Here is a link that might be useful: HMF New Dawn

Mike, I had two 50 ft. lengths of drip hoses wound in, out and around the plants with mulch covering them - all throughout the garden in the veggie garden. The mulch was piled on 8 inches thick or thicker under and around them. I put covers over the tomatoes in late July through August. I have good well water, so no chlorine that can damage plants. Notwithstanding all that I did, when temps reached 110-120, everything just turned brown, and then blister beetles ate what was left. I had tall, dark green, beautiful corn plants with 2-3 huge ears on each plant, but upon checking them, they had few developed kernels. Total loss. I planted more than one hundred tomatoes (seven varieties), corn, beans, cantaloupe, watermelon, bell peppers, three types of hot peppers, Red bells, zucchini, and onions. Normally I get enough to can, freeze, eat fresh and sell at the Farmer's Market & Health Food stores and still have enough to donate to the Food Bank. Not last year. The only tomatoes I got were a handful from the plants I grew in large pots, but only a few. They were sure good though. Cherokee Purples were especially yummy and the Lemon Boys. I think I got about 20 tomatoes altogether. I got more than everyone else around here. Their plants kicked it in June and July. I did get some okra from the plants in the smaller, lower garden and a few pitifully small Early Girl tomatoes, and a pretty good harvest of Jalapenos in September when it cooled down a bit, but that was all. I put so much work into it and expense. But it was just too hot. It was like standing inside a furnace ever day. I lost several small trees, one large weeping willow and several Eponymous shrubs. And what the heat didn't kill, the voles did, chewing the roots off several of my roses. What a horrible year! Sorry to go on about it...

Sweet potatoes are VERY frost sensitive so I would have my doubts even with protection. It is possible that the roots ( sweet potato is a root not a tuber) may sprout in the late spring. They do sometimes here in zone 8. Only good for slips tho and very late. Sweet potato will grow with minimum nutrients. Their main demand is loose deep soil at least 7-8 inches deep. It is the crop we use to plant first in newground ( forest land with trees and brush removed) to bring it into production.