^ You wish you knew how many mgs of WHAT 'it was'? It says above that you have 30mg morphine sustained release (guessing ms contin) and hydrocodone--which MAX come in 10mg. There IS an easy way to figure out the mg...simple search on any search engine. (I can say that, right, mods!?)
If you are used to taking 60mg oxycontin in one dose then you're absolutely right: don't expect a beautiful time, or to get even close to that feeling.
If your tolerance to benzos is small I'd say take .5 mg to 1mg tops. Save them for a different day. Then again, I'm one who never takes benzos recreationally as for me it's not fun at all...strictly a sleep aid or an anxiety reliever (as prescribed, in other words).
Without knowing your tolerance no one can really tell you how much to take (in terms of the opiates). You really should be the one to know that. Use a conversion chart and take the amount you usually take. The benzo on top of that will bring 'something' different to the table.
With sustained release morphine, IV'ing (though, you CAN if you do it the right/safe way--see other threads *many other threads, regarding this topic) is not really #1. You could plug it, if you aren't against that ROA. You could parachute it...don't snort it. Or, swallow it. Why don't you look up morphine ROA in here. There is so much info.
Swallow the hydro - OR, do a CWE for desired total amount. (instructions for this are on this site as well).
Swallow the benzo. Best ROA.