I found the Ortofon's stock silicon tips slightly too thin for secure fit and reliable sound quality. The JVC silicons that come with the FX500/700 are much better, but AFAIK not available seperately. So it would be either UE silicons, UE silicons piggybacked on stock tips or Sony Hybrids with shortened stems.
As for bass extension, all moving armatures I've heard (Ortofon e-Q5/7 and GR10) behave the same way, they roll off rapidly below 50Hz and go pretty much silent below 30Hz. If desired, the Sony Hybrids can be used to increase bass presence (though of course not extension) due to their smaller opening. But at full length they may sound somewhat congested, so you'd have to gradually trim their stem until they sound clean to your ears.