Is there an alternative to the Jabot for a doublet

[McMurdo]

Of course it all depends on the Doublet. For a Montrose for example I think the the Jabot is needed, on mine there is a dart that if not covered by the jabot would be unsightly. So when you do get it pictures would help.

[puffer]

IMHO, there are 2 options for the style collar you mentioned.
1. A silk STOCK (black & white are most common, but colors are also worn.

2. A "NECK CLOTH" ( also called Cravats) These a GREAT white, Black, colors Plus The different looks you can achieve, are "Fantastic
http://people.virginia.edu/~jlc5f/Costumes/Assign11.htm

I wear both regularly, both "uniform & Formal. With my jackets (one "standing collar" & one "open collar (with a military style "standing collar" Vest.) .