Quick reply so I can get to bed, but...
First off, you need to have 77v HPL lamps in your fixtures, not the 120/115v versions. If you are not running these lights without dimmer doublers currently, you WILL need new lamps.
Connector doesn't really matter (electrically speaking) but it is a good way of making sure that only the correct fixture/lamp is being used. I would recommend not switching the connectors; if you DD a fixture with a 120v lamp, you get a really dim lamp, if you run a 77v lamp on a normal dimmer, you get a really dead lamp. The factory installed L5-15's are a good idea, just let them be.
Enabling DD on console is not really necessary,--ANY console that speaks correctly to your dimming system will work (for the most part): for the "A" side, you use the base DMX address (Dimmer 17A responds to DMX 17) for the "B" side, you just add 256 to the base DMX address (Dimmer 17B responds to DMX 273 [256+17]) But having the "A" and "B" is good for the sanity rather than having to add 256 for each address.
Now, you MUST have Sensor dimmers, and you have to set the rack (or individual dimmers if you are mixing DD fixtures with non-DD fixtures) to Dimmer Doubling mode. For this process you should RTFM and possibly give a call to tech services and explain the scope of what you are planning to do.
Are you looking to just DD a few units, or is this a big show/Installation? How many dimmers are you dealing with? if you have more than 2 racks of 96 dimmers I you will need to split them onto separate universes as now a rack of 96 requires 192 addresses (you can see where this is going in the whole DMX 512 thing)
Hope this helps