I'm assuming that the 1000 hours arent on a twin.
The majority of the 135 roles you mention are probably flown single pilot.
To assist as a second pilot on a single pilot certificated aircraft would you need a type rating and an IR?
Realistically without some relevant experience your chances of walking straight into a 135 position are very slim - be that two crew VIP (as most are single pilot), and your opportunities are even slimmer in an unsupervised SPIFR role.
On that basis I'd be inclined to go for the cheaper 355 option. You stand a better chance getting some VFR 355 work.
Just my opinion, good luck.