When looking at a volume builder aka project or spec builder, you will normally come across many different floorplans and facades. You can normally search through how many bedrooms you would like as well as the size of the home.
I would suggest understanding first what size frontage (width of your property if a regular shape) you have and what setbacks are applicable in your council or through CDC. This will help narrow your search. Also know what size property you can build because there are strict limits that apply, again this can be found in your council or CDC guidelines.
The larger builders will normally have a number of display homes which will help give you a sense of what they can build and how the space feels.
A lot of them also have 3D virtual tours that are great too.
A word of warning, the display homes have many costly upgrades which can add 2-400k over the base price.
Facades on their page might not also include rendering which can cost thousands extra and to the sales rep may not mention any of this until you’re much further along. For instance Wisdom Homes shows their New England facade with render and when they give you a cost for it they won’t mention it’s not included. It’s only after seeing the plans that it’s obvious.