Insulated Shipping Box appropriate size

This may be a stupid question but I'm getting ready to order some shipping boxes and I'm wondering what a appropriate size shipping box for a BP hatchling about 1-3 months old?

Would a 7x7x6 box be big enough?
http://www.tsksupply.com/products/7x...pping-Box.html
If so what is the biggest size BP (I guess in grams) you would ship in this size box?
And at what size would you bump them up to a 12x9x6?
http://www.tsksupply.com/products/12...ping-Box-.html

Also, is there a huge differance between 1/2 inch foam and 3/4? Is 3/4 really necessary or is it overkill?

Thanks in advance guys, I appreciate any input.

The smallest I use are 12x9x6. The smaller ones are too small, IMO. I have shipped a 2500 gram girl in a 12x9x6.

In regards to size, Eddie exacted my sentiments. As far as insulation goes, anything smaller than 3/4" in my opinion is garbage. Think about it, sometimes you may be shipping a $2000 or more snake in that box. Does the extra pennies really make that much difference. The whole purpose of an insulated box is to keep a stable temp for the snake inside. #/4" is your best bet a regulating temps in the box. We used to use 1/2" years ago, and after my first order was depleted, I never ordered them again. You won't be able to ship in either extreme with the 1/2".

I hope that helps,

Thanks for the input guys, right now I'm looking to order a kind of beginner BP shipping kit. My aim is to use this kit for shipping BP's ranging from hatchlings to about a year old. My goal is to order this stuff all at once to save some money on overall shipping costs for the order.
So far I have:
12x16 cloth snake bags
12x9x6 insulated shipping boxes w/ 3/4" foam
40 hour shipment warmers

Anyone know of anything I'm missing?

And just a couple more questions:
Does anyone recommend TSK or superior enterprise or any other company over another for shipping supplies?
Also do you guys feel the size of the bags and boxes would be appropriate for shipping BP's up to about a year old?

Everything I ship is shipped with 3/4 inch insulation.

As far as box sizes I use 12x9x6 for BP it give them the space, cushion, and insulation need year round.

The only time I use 7x7x6 is for colubrids shipped in daily cups.