Last time I looked, 20% above the basis amount up to around a million dollar limit.
Unless the have changed just recently, that's the number.
Find a good VA lender in your area.
The VA loan is 100% up to the county limits.
San Diego County limit is $437,500.
Anything over the limit requires a 25% down payment of the difference between the county limit and the purchase price.
example: $500,000 - $437,500 = 62,500 x 25% = $15,625 down payment.