In Thessaloniki you must decide if 19.2E is of bigger importance for you or 28.2E/28.5E. Both positions do require 1.20m dishes for proper reception on the easier beams which are all except Astra 1F and 2D. So receiving the other in the offset weakens it a little. Aiming at 19.2E will give you better reception also at 13E and 16E if you decide to get also this. Aiming at 28.2E will improve this and 26E or 39E. The compromise is as Nektarios 1451 wanted to point out, that putting 23.5E in the center will allow you to balance the signal loss from all positions. On the one hand 23.5E is excellent because it's on the meridian Thessaloniki is located, on the other hand the reception results are poor on such a smallish dish. A 1.80m would get full Astra 3A and for 1E you would need 2.30m. But you should be able to get some frequencies also on 1.40m. Depending on the multifeed-capabilities of the dish you should be able to get +/- 10-20°, which means expect a reception window from 13E-33E in worst case and 5E-42E in best case. The better the focus of the dish is, the weaker the offset positions. And closing with the amount of LNBs you can add on such a dish, i know people that have 5 LNBs on a Gibertini 1.25m but if you have time and talent 10 LNBs should be possible as well. Depends on how easily it is to fix them.