I am sure that has just confused the OP a little despe666.
swapping your 3100 for a 6100 requires no changes
OK, I agree, IF the OP has an SW44.
Then you add;
If you swap the 3100 for a 6100 however, you will have a problem
Nope, that is the same as above. You mean, "If you swap the 3100 for a 9242
however, you will have a problem. Yes I agree.
Then you suggest looking at DP equipment, while I know it does work and work well, the OP has already said that he is a Novice, so IMHO adding another level of confusion is uneccessarry.
If the OP does choose DP & DPP equipment and has a problem, bell will not be able to help, as they do NOT use DP LNBF's or DPP44 switch's yet, I would suggest this route is best left to more experienced "novices".
Whilst Bell TV do NOT use DP LNBF's they DO use DPP Twin LNBF's that can feed a DPP44, just as an FYI.