Oh! So if I were to reduce the switching speed, I'd have to go for an expensive inductor and if I were to keep it the same, I'd have to go for a bigger transformer which is again very expensive!
Any ideas on how I can resolve this conundrum?
Also, the lowest Rds P-MOSFET I could find in a price range that is fairly acceptable was 62mR. This gives me a power dissipation of about 4W at 8A. Also this is the inrush current and not the normal operating current (which is about 5.5A. At which the power dissipated is about 2W). Not too sure if I'd still need a heatsink here.