Reddit mentions of Boutell's heraldry

(a) If your family immigrated to the United States prior to September 3, 1783, he can receive an "honorary" grant of arms from the British Crown. The "honorary" part just means the right of arms is not legally enforceable in British courts (though it's been more than 50 years since anyone has tried to enforce arms in a court, so this is really quite an incidental point), but is in every other way an actual grant from the Crown and comes with the elaborate letters patent (https://i.pinimg.com/736x/fc/79/f0/fc79f0783aa6435cc1242b6f05d45ca9--arundel-illuminated-manuscript.jpg), permanent recording in the archives of the College of Arms, and the right to matriculate them to his children, and their children, and so forth in perpetuity. They also handle all the design work (which also means you can't submit your own; they create the blazon as they feel is appropriate). This can be expensive, however. Generally about $6,000 for the grant, plus $150 for each generation removed from September 3, 1783, which covers their cost of confirming pedigree.

(b) If you want to assume arms, you can hire an heraldic artist. Here is a list: http://www.heraldic-arts.com/index.php?option=com_content&view=article&id=11&Itemid=144.

(c) If that's too pricey and you have only minimal graphic/design abilities, I recommend purchasing a license to Armorial Gold (http://www.heraldryclipart.com/) for $78 and then downloading the free edition of Serif DrawPlus. With a bit of effort you can make a quite nice-looking emblazonment. You should also purchase a used copy of Boutelle's Heraldry (https://www.amazon.com/Heraldry-Charles-Boutell/dp/0723217084) on amazon.com which will teach you how to correctly blazon (textually describe) the arms. Or just describe them here and someone can try to blazon them for you.

(d) If you like, after doing 'b' or 'c', you could even have the arms registered with the South African Bureau of Heraldry (http://www.national.archives.gov.za/PERSONAL%20HERALDIC%20REPRESENTATIONNew.pdf) which gives you an elaborate looking registration certificate (http://www.heraldry.ca/arms/s/sidselrud_certificate.jpg) issued by an actual government (but, more importantly, results in the arms being archived in a permanent format; that is, the record of the arms will exist as long as the Republic of South Africa exists, unlike some of these internet registries which last only until the guy running it gets bored or dies or forgets to renew the domain name). This can cost around $500 (though, I believe, this includes a professional rendering of the arms by a South African herald). South Africa will only register heraldically correct arms so it would be good to get someone experienced to review them prior to submission. An important distinction between 'a' and 'd' is that this is a registration, and not a grant; that is, the Republic of South Africa is simply acknowledging that you have assumed arms and recognizing your legal right to use them, as opposed to 'awarding' (granting) them to you as in the case of the UK.