Time for an update!
First a big thank you to everyone who posted excellent advise. Especially the Satellite Calculator and the hint about Non-Penetrating Roof Mount helped a lot.
I got all the kit and installed it Saturday/Sunday. First a word of warning: The FalconSat webshop is rubbish - they didn't ship my order and didn't reply to my emails for 2 weeks. At the end I got fed up and ordered the kit from elsewhere and had it the next day!
Assembling the dish took a couple of hours with my limited experience. The instructions were photocopied and some of the details were impossible to make out on the photos so a bit of guesswork was needed, but I got there in the end.
I asked in an email to one of the webshops what size pole was needed to mount the dish on. They said 2". So I happily bought the Non Penetrating Roof Mount, which is 2", but unfortunately the dish needs a 60mm pole (about 2.3 inches) - when will we ever get rid of metric/imperial confusion!?
I fixed this by cutting off a bit of the pole from the patio stand supplied with the dish using an angle grinder and mounting that over the top of the pole on the NPRM using rubber tape to stabilize it and silicon to seal it in place. This caused the angle to be off from vertical by a small amount (I guess about 1 degree) but this proved not to be a problem.
Before I mounted the dish I set the skew angle and mounted the LNB's according to the Toroidal Calculator output. Then I put it up on the mount and angled it to the central satellite 13E based on my dishpointer.com printout. It was very easy since there was some clear landmarks to aim it for.
Then I connected the SatFinder to the center LNB and my tuner card in the other end. After moving the elevation up and down a bit I got got a 10 signal!
Then I tightened the elevation nuts at what gave the highest signal (after turning the sensitivity down). I then fine tuned the azimuth but it was almost spot on from the outset.
After that, I connected the satfinder to the other LNB's. Amazingly they all came up with a high signal straigth away, except for one (the 0.8W satellite)! I moved the 0.8W LNB slightly on the bar and then it too came up with a maxed out signal.
The whole process of aligning the dish, took about 5 minutes! And this is the first time I have ever done this. Without the Toroidal calculator and the Dishpointer website this would have taken much, much longer.
After tightening up everything I then connected 1 output from each LNB to each of the switches. Then it was MythTV time!
Setting up the switches and LNB's in mythtv-setup was intuitive and easy. Unfortunately nothing worked (scanning/tuning) after that
even with dvbscan I got nothing.
This was with the latest Linux kernel's stock v4l-dvb drivers (2.6.29.4). I found out after some Googling that the Linux drivers for the TechnoTrend Budget 1600 card were quite new and didn't work very well, especially when LNB switches were involved. So I tried with the linuxtv.org Mercurial repository v4l-dvb drivers. No luck.
I googled some more and then found a German guy who had his own v4l-dvb repository _http_://www.jusst.de/hg/v4l-dvb/
THIS worked! (make && make install && make load and the drivers were installed).
MythTV now scanned all the satellites without issue and I found more than 900 unencrypted channels in total (including BBC HD and the foreign channels I was looking for). Comparing to Lyngsat I think I have all of them. On my Frontend I tried watching some of the channels and every single one worked without glitches. The only thing is that the Signal Strength always shows at 99% but I think this is a driver issue with the TT card (and will probably be resolved at some point, the drivers are only a month old!)
So all in all I am extremely happy with my new system and everything worked out. Again thanks for the help to all of you guys! If anyone is thinking of installing a similar system I'll be happy to help with my experiences.
Cheers
Descore