I were posting from the phone hence the short reply.
Regards capacitors you are looking for:
1.105C instead of 85C to last longer in the heat of engine bay or lamp wherever you fit them
2. 25V as 16V is a bit too close for comfort
3.4700 uF or 10,000uF. 4700 will be smaller and fit more nicely and should do the job, 10,000 might be needed if battery is getting really weak.
Example:
http://www.ebay.co.uk/itm/25V-4700uF...#ht_970wt_1163
They should do the job nicely. Just make sure you wire + and - correctly