So the reservation really just sends the dealer a notification you're interested in the truck. Doesn't really commit you to anything at all. After that (assuming they contact you), you can decide to go place an order to however you want the truck (trim, color, etc).
Some dealers require deposits anywhere from $100 to $1000, just really depends. Some don't require a deposit at all. Most are fully refundable meaning if the truck comes in and you hate it, they'll give you the money back and put the truck for sale on their lot.
Even with an order placed, you're most likely not committed to anything. Just confirm if the deposit is refundable if you don't like the truck. Dealers will not have problems selling these, so most won't care if you back out.
Also - you can probably just call dealers around you and ask if they can help you place an order rather than waiting on them to respond to a reservation request.
Some dealers require deposits anywhere from $100 to $1000, just really depends. Some don't require a deposit at all. Most are fully refundable meaning if the truck comes in and you hate it, they'll give you the money back and put the truck for sale on their lot.
Even with an order placed, you're most likely not committed to anything. Just confirm if the deposit is refundable if you don't like the truck. Dealers will not have problems selling these, so most won't care if you back out.
Also - you can probably just call dealers around you and ask if they can help you place an order rather than waiting on them to respond to a reservation request.