The 100/20 will be good up to a 300 watt panel. I have the 100/20 on my 270 watt. On a couple of occasions this summer it topped out at 274 watts, exactly 20a.They quoted me on a Photonic Universe 350w mcs certified semi flexable solar panel at £450.00 and a Victron MPPT 100/30 at £110. Fitted without cost to me. Total cost £560. Not counting 4 journies from Nottingham to Derby to drop the van off and then go back next day to collect. I have allowed a few quid for unexpected costs and rounded it up.
However, I have no intention of taking this up, I have a sytem that is almost new with a Victron hppt 100/20 control box. The only thing that has failed is the panel.I don't want to retrace my path a 3rd time with a flexi bonded panel. I want to go rigid.
I did get a 100/30 to get a few extra watts, but it was too big to neatly install where I wanted it. That one is now with a beloved lucky(!) member in sunny Benidorm.