Two answers:
1) You order to your heart's content and wallet's tolerance from The Early Music Workshop of New England, the retail shop of The Von Huene Workshop, makers of some of the very finest recorders.
If you're overwhelmed by the variety of choices at that link, allow me to recommend picking up the phone and calling them when they're open, and asking what the person on the other end of the line recommends. Their shop is, perhaps unsurprisingly, staffed by a lot of serious recorder players -- including being the "day job" for some pros -- who are also some of the nicest people. If, by chance, your call happens to be answered by, say, a harpsichordist, they'll go find someone who can make recommendations to you.
(BTW, if you're ever in the Boston area, do visit the shop in person and go on a tour of the workshop too, if you can. It's a treat.)
2) You mention Renaissance music. One of the important details about Renaissance instrumental music is that a lot of what comes down to us is dance music.
I don't know if you are still at this point looking for easy tunes, but compilations of Renaissance dance music can fit the bill. You might find, for instance, Orchesography from 1589, most of the tunes of which are short 8 bar and 16 bar things, fits the bill. There's a cheap Dover edition, and it's not uncommon to be able to find used copies for pennies; note that the music in it is in the original notation, which is slightly different than you're used to. Most of the tunes in Orchesography can be found by judicious googling. Once you're looking for more complex tunes, The English Dancing Master (by Playford, 1651) and De Pratica Seu Arte Tripudii (by Ebreo, late 15th cen.)