Microlams will need to be ordered whether you buy from a big box store or a local "real" lumberyard. 5-10 day lead time is required. Tell them your needs and they can look up what specs are required. Keep in mind that any beam this long, whether metal or wood, will not be cheap. Expect this to run $600-1000
One nice advantage to buying a wood solution is that virtually every wood seller offers curb delivery for $59 or less. Depending upon your trailer/towing situation, the ability to have someone else deliver a 30' beam into your residential driveway and use their forklift to unload it is very attractive.
I don't think you will typically find steel or aluminum dealers doing curbside deliveries to residential areas with 30' lengths at all, much less for $59 The key word here is residential. Over the road freight companies have surcharges for residential delivery running from $50-150. The cheapest way to get anything big delivered is by a lumber yard style delivery truck with the piggyback forklift. The delivery guy from Home Depot spends half his day making residential deliveries and is used to homeowners pointing to the exact spot where they want something put. A 30' beam on the back of a lumberyard truck will travel there easily. A typical homeowner has access to flat trailers 16'-20' long. That still leaves 10' or more sticking out the back.
That will not go over well in traffic or with the local cops/DOT.
