From JSA to JSB to Short-Term Enterprise Allowance

So this is kind of complicated question...

I want to start a business in March of next year (5 months away). Just before I start the business I hope to start claiming Short-Term Enterprise Allowance.
The problem is you can only claim a combination of JSB and STEA for a combined maximum of 9 months. I would like to claim this benefit for the first 9 months the business is running.

Which would be fine, but I've just lost my job and am most likely going to have to sign on.

The ideal situation would be to sign on now to JSA. Sign off in February, and then sign back on to JSB and subsequently STEA in March (and stay on it for 9 months)

Messy!

So my question is: Will I be able to sign on to JSA so as not to use up my credits for JSB/STEA?

Does going on JSA eat up my entitlement to JSB?

Can I chose which JS to go for?

You won't be able to go straight to JSA if you qualify now for JSB, you will have to exhaust your entitlement based on your PRSI payments before you will be assessed for the means tested JSA.