Out of your choices, I'd go PSA as well. BCA is just too hit or miss from member experiences here. You may think about putting one together yourself. It is not difficult, there's a ton of info here and a multitude of YouTube videos to assist.
If you shop around, you may be able to personalize your upper for a similar cost. A quick search revealed this, https://www.schuylerarmsco.com/christmas...ne-2470424. Different rail lengths are available to suit your needs. Add a group buy barrel, of your chosen length, from below on this site. Throw in a gas block and tube, then a ToolCraft BCG, https://www.armorally.com/shop/toolcraft...ier-group/, and you're golden for your stated purpose.
If you shop around, you may be able to personalize your upper for a similar cost. A quick search revealed this, https://www.schuylerarmsco.com/christmas...ne-2470424. Different rail lengths are available to suit your needs. Add a group buy barrel, of your chosen length, from below on this site. Throw in a gas block and tube, then a ToolCraft BCG, https://www.armorally.com/shop/toolcraft...ier-group/, and you're golden for your stated purpose.