Hey there,

I haven't crossed any of these borders myself, but this should be easy,straightforward procedure. I recently cycled through Laos into Cambodia, having been to both, Savannakhet and Pakse. From Thailand to Savannakhet there is both, Boat and Bridge available, whereas further south, it is about 40km from the border to Pakse. There is also a bridge over the Mekong at Pakse. Savannakhet is a nice place to hang out for a couple of days - but that's it. Furthermore, the stretch from Savannakhet to Pakse is not so interesting and there are not many guesthouses on the way. Better go straight into Pakse and go to the Bolaven Plateau instead or spend a few days on Siphon Don (4000 Islands). When you head south from Pakse, don't miss out on Wat Phu, a small but very nice Khmer Temple close to Champasak. Also the ferry ride is good fun. Road from the border to Stung Treng in Cambodia is asphalt now. You can find a few drinkstops along the road. From Stung Treng to Kratie is also asphalt and it's about 150km without guesthouse inbetween.