[mopi]

I have BBM working on an android phone (nexus4). I use a UK SIM and an Irish SIM in the nexus4 as I travel between the two counties a good deal. I currently have BBM working on the nexus4 regardless of which SIM is in the nexus4 which is just the way I want it.
The UK mobile phone company will allow me to add blackberry support (BIS) to the UK SIM on a month by month basis for a small fee. With BIS paid for I get a data allowance (BIS only with means blackberry email + BBM) of 10MB per day -- world wide ! A seriously good deal IMHO.
I have a long haul trip coming up and I'd like to buy a blackberry phone and get the BIS addon on my UK SIM. I will put my Irish SIM into the nexus4 and use this in wifi areas and for SMS.
I have read that the way the blackberry PIN works changed between BOS-6 and BOS-7 but as I do not have a BB phone the details are lost on me for the moment.
Can I get BBM to work on a blackberry phone [say a 9320 or older phone] with the UK SIM and have the same BBM account working on the nexus4 with the Irish SIM (plus WiFi), I really want to avoid a multiple BBM accounts. I do not intend to use BBM on both phones simultaneously.
BOS-10 phones will not meet my requirments as they 10MB/day allowance does not apply to them.

Pointers appriciated, I really like BBM and hope to convince friends to ditch WhatsApp and switch.

Paul