Goillini,
How heavy (or light) a gun do you want?  I just sold my RBL 28.  It did not fit me and was too light for me to shoot well consistently.  I would look at a Poli.  They will make barrels up to 32" and their single trigger is good.  The Basques will build you whatever you want.  I don't know about their single triggers.  If you think you want a 5.5# gun spend some time with one or two before committing to a custom gun.  I would love a 6# 30" 28 gauge that fit me.  I'm just unwilling to commit the $$ required to make that happen.
Regards
Jeff