widest blade for a bandsaw?

I have a similar saw, but a little larger that can handle a 1/2 inch blade, but I'd suggest the 3/8ths as well.

Here's a chart of maximum radious curves to blade width. Below that is a stone I use to round that back of the blade so it turns more easily.

I have the Rikon 10" band saw. I use the 1/2" woodslicer blade to resaw with. 1/2" is the widest blade that can be used on this size saw.
I have made blades, using 1/4", and 1/2" material- 2-3TPI blade stock.
All sizes have worked well.
I just purchased a 100' roll of 1/2" 3-TPI blade stock from Victor Machinery $78+shipping.
They have many widths and tooth configurations to choose from, if you want to make your own.
There are weld kits available, commercially.
Braise not weld. No heat treating or annealing required.
Just offering some options.
I just made a blade for my Jet 18" bandsaw using the 1/2" material. The blade is 150". I just re sawed 14- 15" wide boards that were 19" long. The blade is still sharp and ready for more!

I use half inch Timber Wolfs on my little Rikon saw and they work well. Tensioning is the key to doing resaw work. I can resaw a 5 inch thick piece, but it is mighty slow going and there's some plane work to do after, so allow for that extra bit of thickness you're going to scrape off.