Hors D'oeuvre, sit or no sit?

I would have different types of seating, some high-top, some low (for kids or elderly guests) and possibly some lounge seating if space allows. Every butt needs a seat no matter the serving format.

I would strongly urge you to reconsider the cash bar, that is not considerate to your guests at all.

ETA: 5 to 8 is dinnertime. Can you move it to 2-5? or 8-11?

You absolutely need seating. I would not stay long somewhere that I had to stand for 4 hours.

I am not even going to touch the cash bar thing.

Without some place to set down your plate and belongings, how would you be able to dig into your purse or wallet to pay for the drinks?

There has to be a seat for every person. Also, I'd be extremely unhappy if I was told to eat before a 5-8 reception. When exactly am I supposed to do that if I need time to get ready for the wedding and then drive- 3:30? Otherwise I have to wait till 8:30 or 9 to get food? No way.

We either wouldn't go, or wouldn't stay long. Likely wouldn't give as much of a gift either if I actually have to go buy dinner someplace else since I'm hungry.

Few things:

1. You need tables/seating for all guests. People will want a place to eat even if you just have appetizers since it is hard to hold a plate/drink and eat. Also, people will want a place to put their purse, etc. and will want to sit and relax a bit especially ladies that are in heels. Also, consider the elderly who may not be able to stand for long periods of time.

2. If you are only having apps you need to move your reception time to a non-meal time. Like a pp suggested you should consider having it from 2-5 p.m. or 8-11 p.m. instead. If not you should provide a full meal to your guests. Having it over a meal time and telling guests to eat prior is inconsiderate. If you have any guests who are driving to your ceremony you may be asking them to go without food from lunch until late evening because they will need time to get ready and then drive to the ceremony leaving no time to eat prior.

3. You should reconsider your cash bar. It is rude to expect guests to pay for any part of your reception. The reception is a thank you to them for attending your ceremony and they should be well hosted during this time. Guests should not be opening their wallets at any point. This means at a minimum you should be hosting a limited selection of beer and wine free of charge for your guests. If you cannot afford to do so you may need to consider cutting down the number of guests you host or eliminating other non-essential costs (favors, uplighting, expensive decor, etc.) to make room in your budget.

Yes, you should provide seating. You can have high tall tables, and sofas, something with a lounge vibe and make it look classy. But have enough so that people are not standing or waiting to find a seat.

I do have to agree with people 5 – 8 is dinner time, and even if people eat beforehand they will be starving. If they start getting ready and driving for your ceremony at around 4:00 pm the latest they will be able to eat is at 3:00 pm, by 6:00 pm they will be starving and so will you. Consider changing the time or adding heavier appetizers (full meal would be better).