Totem pole Bjt based Mosfet Gate driver

Question

I need to design a totem bole bjt based gate driver for Mosfet IRF640, which is going to be used in a Buck converter.

I know the peak gate charging current= 1A.

I've already selected my complementary Bjt pairs (2N2222A,2N2907A) so it can give a max current = 0.6A.

The mosfet has a minimum \$V_{gsth}\$ = 2V and max of 4V. Now how do I select Rg? Rg = [Vgg - V(gs,Io)]/ig.

From the equation:

1.On no load, I get Rg = [15-4]/0.6 = 18.33 ohms

2. On full load (Id=10A), V(gs,Io)=5.5V from datasheet, so Rg =[15-5.5]/0.6 = 15.84 ohms.

3. Considering -Vgg = -5V, I get Rg = [15-2-(-5)]/0.6 = 30 ohms.

Where should I use the peak gate charging current value of 1A?

Thanks in advance.