That's incorrect.

The L358 works as both an incident light meter and flash meter (pretty much just like any other flash meter).

In addition, the L358 is designed to accommodate a Pocket Wizard compatible radio module (Sekonic RT-32... or RT-32N in N. America) to be able to wirelessly trigger your studio strobes or flashes directly from the meter.

However, there are other radio modules available. For example, RadioPopper makes one (SK-TX) that costs about the same as the PW module, but is usable with their Nano triggers, which at about $50 apiece are considerably less expensive than Pocket Wizard transceivers (about $150 each). The RadioPopper Nano are pretty simple, 4-channel radio triggers. Comparatively, some Pocket Wizard triggers have as much as 32 channels, and some can be set up in zones (which may be handy to selectively fire strobes, such as when setting light ratios).

Plus, L358 can be used as a flash meter in several other ways. In the lower righthand corner of the front is a standard PC sync cord socket that can be used wired to fire test shots.

And, that same socket could likely be connected to some of the more generic brands of radio triggers to wirelessly fire test shots.

Built-in triggering is just an added convenience, whether it's wired or wireless. You could simply activate the meter, then trigger the flashes with something else (optical or radio). Flash will take a reading, as usual.

With the L308 I believe you'd either have to use it wired or with some form of external triggering. It has no provision for any internal radio modules at all.

I like that the L308 uses one standard AA battery for power. The L358 uses less common and more expensive Lithium CR123 battery (but RadioPopper transmitters and receivers use CR123 batteries, too).

The L358 has a rotating head, to allow the receptor to be positioned a number of ways. The L308 doesn't.

Probable the main reason the original poster might not be interested in the L358 or L308 is that they are primarily incident meters (both able to be used as reflective meters too).... NOT spot meters. There are 1 degree and 10 degree accessories available for the L358 (as well as a lumigrid for reflective metering).

If I were the OP, I'd look into getting the Pentax spot meter fixed and continue using it. I prefer a separate spot meter. (I have the old Pentax Spot Meter, too, as well as an even older Soligor Spot Meter).

Sekonic meters are quite good. I'd also suggest looking at Gossen, Kenko (formerly Minolta and Konica-Minolta), and Polaris. They all make some good models.