Heritage of Scotland does a nice jacket & waistcoat, and has a good slection of tweeds. The price is also VERY nice! Be advised however, they're part of the Gold Brothers chain, and other members can verify that you take a chance with them. The quality is good and the fit also, and doesn't seem to heavy for hot weather. Also be advised that if you're not sure aboiut the color from the sample page, purchase a swatch of the color you have in mind to be sure. I recently bought a jacket & vest from them that I thought was grey and it turned out to be lovat blue. HOS claimed it was my fault for not purchasing a swatch first, so they refused to take it back. I had to sell it here on the forum.
That being said, HOS's tweed color choice is quite good, the quality is acceptable, and the price can't be beat. Also, remember you'll have to pay duty, because they ship FedEx, and it cost me $76!