The friendliest when it comes to asking for quotes/estimates are shopping mall japan and crescent/noppin imo, but I am not sure with Noppin anymore with the changes. EMS is my choice all the time due to the status of our post offices here, but I agree that unless your order a lot/something bulky, it's really expensive compared to airmail/SAL.

I have tried preordering from SMJ/Celga/Crescent and asked them specifically to hold them until I complete all my items so they can be shipped together. They didn't bug me for having my item stocked there for a long time or charge me extra (since some shopping sites do charge you for not having your items shipped immediately o.o).