For printing with ABS, especially in a visitor area, you need a good ventilation system and a closed-box design machine - the fumes are harmful and unpleasant. I recommend the CEL Robox and Witbox 2 for ABS:http://robox.cel-uk.com/robox/rbx01.htmlhttps://www.bq.com/en/witbox-2
In my experience, PLA parts are mechanically just as good as ABS parts, moreover they release only a slight but pleasant fume not unlike fresh bread and are foodsafe and biodegradable.
Even though Ultimaker gives the most reliability and best print results, for the steep price point I would rather go for a Lulzbot TAZ 4 (if you can find one) or 5. If I were in your shoes, for that budget I would buy two Ultimaker Original machines and upgrade them with dual extruders - those are still fantastic machines and you can find some used ones almost good as new. I have used mine with great results over the past 3 years and it still works wonderfully. Or a larger printer together with a Wanhao i3. Especially for a business there is great value in having multiple print jobs running simultaneously.
Also don't put it next to your bed unless you have good earplugs