Down to the byte level, I'm not sure, but if you can get an all ECC chain (or as much ECC as you can get, gorkish points out below that all ECC isn't practical), those certs are gobs shorter than RSA certs, because the public keys are shorter.
Otherwise, any CA that's been around for long enough should be able to give you a cert signed by an intermediate signed by their trusted root; so you would just send clients your cert and the single intermediate cert.
You should only have a chain longer than two certs if you need to cross chain to another root; but so many of the older clients that needed really old CAs were forced off of PKI because they don't support SHA256 signatures.
Otherwise, any CA that's been around for long enough should be able to give you a cert signed by an intermediate signed by their trusted root; so you would just send clients your cert and the single intermediate cert.
You should only have a chain longer than two certs if you need to cross chain to another root; but so many of the older clients that needed really old CAs were forced off of PKI because they don't support SHA256 signatures.