apparently there is no right or wrong answer here as people have very different opinions on this subject. i made it very clear what i thought in post # 22. but this just my OPINION and you are most likely looking for the answer you WANT to hear.
if youre gonna do a 210/220, i would definitely take the extra foot of lenght over a few inches of height. the height of the tank is not gonna help much as silvers tend to stay towards the top of the tank anyways.
again, in my opinion, i say that silvers should be kept in a 240 bare minimum and jardini's in a 180. with that said, i have my silver in a 210 (7x2x2) and i plan on keeping him there for a very very long time unless i find a good reason to get something bigger.
so again, my short answer to your question is NO on the silver and YES on the jardini. you can either listen to what i say or ignore it. makes no difference to me.
good luck