I would like to get started by saying Im a huge huge fan of Gypsy Jazz and have been for 30 years,
been a blues and British RnB guitarist and slide player for a long time but my heart belongs to Gypsy Jazz, so a new chapter in my playing life begins.
Please pointers for good tutors online or otherwise, and a a resource for a nice guitar in the UK £300-500 mark.
I am based in Essex just outside Greater London.
One of the basic books for this style of lead playing is Gypsy Picking. Available from the store here. The resources have ballooned over the past decade.
As to rhythm playing,wow therefore so many avenues now. Dennis Chang's DVD is a classic. A number of others who post here do online lessons. You can even learn from one of the best in the world Nous'che Rosenberg, at the Rosenberg Academy.
How you best learn will dictate what avenues you want to pursue. Check out media tab at the top and you will see what I mean.
Some decent gypsy guitars come along used in the classifieds from guys in the UK. Easier and way cheaper. There are some posters here who know the scene in e UK and hopefully will jump in with some stores to check out.
As far as books go, I second gypsy picking. I would also recommend "getting gypsy jazz" by Stephan wremble, and study the hell out of the arpeggios as well as the upper/lower approach. Also, the Gonzalo how I learned books are great for phrasing and note maps.
Before any licks and phrases though, you need to be able to see where all the chord shapes are over all the changes in at least a few songs like minor swing, all of me, sweet georgia brown, dark eyes, etc, and nothing works to get that down better than playing your basic arpeggios over the songs changes. Dennis chang calls it the skeleton exercise. I found licks and stuff useless until I got the hang of that. Stephan Wrembles book has a whole section on arpeggio practice that I highly recommend.