I would say both of yours alternatives are at least grammatically questionable.

Unlike C’est which can be and is routinely followed by a plural, ce qui is almost exclusively followed by a singular.

Even while rising since the nineties, ce qui sont occurrences are still very low (< 2%) compared to those of ce qui est so using the form risk being frowned upon or considered outdated.

Moreover, some ce qui sont found by google books are false positives or obvious mistakes, e.g.:

…plusieurs des instances formelles (DS, CPPT, CE), qui sont encore dénommés…

…mettent sous pierres le corps de ce qui sont partis dans le monde obscur. (should be ceux)

If ce qui needs to be kept, I would recommend rephrasing the sentence that way:

Je vois ce qui est un ensemble de choses intéressantes.

Grammatically, the correct phrase is “Je vois ce que sont des choses intéressantes“.

“ce que” is the subject of the verb “sont” and it refers to the nominal group “des choses intéressantes” which is on plural form. That’s why the verb “sont” is on plural form too.

Then, I use “que” instead of “qui” because “des choses” are an inanimate object and “ce que sont des choses intéressantes” is the complement of direct object of the verb “vois“.

• “qui” : use for animate or inanimate subject and for animate complement of direct object

for example :

“Je vois ce qui fait un homme” => animate complement of direct object of “vois”

“Ce qui est difficile, c’est de bien expliquer” => inanimate subject of “est“

“Qui est-ce qui est arrivé encore, c’est Marc” => animate subject of “est”

• “que” : use for inanimate complement of direct object

for example:

“Je vois ce que fait un homme” => inanimate complement of direct object for “vois” and here I used a singular form example with “un homme” and “fait”.