No, you cant really substitute eq for deca. Two very different compounds, and if you are looking for "deca-like" results than eq will definitely disappoint. However, eq does bring its own set of results that may be appealing. You wont get as much size or strength from eq, but what you do get will be much more "keep-able" than what you get from deca, at least from my experience. Eq will NOT make you bloat at all, and will actually help you lean out if used properly. Eq is similar to deca though in that it needs to be run for a LONG time to see results.
If you choose to go with eq you need to run it for AT LEAST 16 weeks at a dose of 600-800mg a week MINIMUM. That seems like alot of juice but trust me, any less than that and you are just wasting your money. Also similar to deca is the fact that with eq you need to run you test longer so that it has time to clear your system before you can begin post cycle therapy (pct). Run your test three weeks longer than the eq.
Good luck man, if i were you, id definitely wait for the deca, a much better compound at least to me, alot of people end up disappointed with eq. Maybe ask your guy if he has npp? gonna be more expensive than running deca but then at least youd be literally running the same compound, just a different ester attached.