Have had LED sidelight bulbs in for a couple of years, the high brightness wedge base bulbs should be available from any decent motor part shop or t'internet.
The best thing I ever did was to buy some rectangular white 8 LED clusters from Maplins at about £18 a pair and mount them either side the number plate, just use a vampire connector (IDC) off the side light circuit with a 2 amp inline fuse and they are about 100 times brighter than the sidelights and I use them in conditions where I don't really need dipped beam but I feel better with them on, and use them most of the time because silver cars seem invisible to some drivers!
