The SMX-K45 and SMX-K40 are both standard definition (SD, 720×480) camcorders with a 52x optical zoom and optical image stabilization. Sounds like the recording quality may be decent enough on both devices to do web videos. Then again youtube quality has gone up.
The SMX-K40 records only on removable flash cards, while the SMX-K45 has a 32GB SSD. The smx-k40 will cost you $329, while the smx-k45 will cost you $499. 16 Gb is probably all most casual users will need.